Informed Patient: A Better Way to Detect Infections in Donated Organs

By Laura Landro

With growing concern about infectious diseases in donated organs, the Centers for Disease Control and Prevention is due to release next month draft guidelines for reducing transmission of hepatitis C and HIV through solid organ transplants.

While the guidelines are still under review, they are widely expected to reflect the results of a new study led by CDC researchers that concludes the use of a rapid assay known as nucleic acid testing (NAT) could significantly reduce the rate of undetected hepatitis C in deceased donors. The study calculated the prevalence of the two viruses in 13,667 potential donors managed by 17 organ procurement organizations over a five-year period. It estimated that a striking 18.2% of potential donors considered at high risk for hepatitis C and 3.45% of donors considered at normal risk could be infected with the virus.

NAT can detect an infection acquired seven days before testing, while standard blood tests (known as serologic testing) measure antibodies to an infection that may take months to appear. Antibodies to hepatitis C, for example, may not be detected for as long as 70 days after exposure. NAT is required for screening donated blood and tissue for both viruses, but the CDC’s upcoming guidelines would be the first recommendations to address the use of NAT screening in organ donors.

As of 2008, only about half the 58 organ procurement organizations in the U.S. voluntarily performed NAT tests for HIV and HCV on all or at least some potential donors, the study says.

Study co-author Matthew Kuehnert, who oversees blood transfusion and transplant safety at the CDC, tells the Health Blog that the high prevalence of hepatitis C among donors in the study combined with the time lag for the serologic detection test raises serious concerns. “The transplant community is the most technologically advanced field, yet they are not using the most technically advanced screening test,” he says.

Among the barriers to wider use of NAT screening are worries about its cost and the false-positive results that may rule out otherwise usable organs. Tom Mone, chief executive of OneLegacy, the nonprofit organ and tissue recovery organization serving the greater Los Angeles area, says that serologic testing alone — which must be done to screen for other issues — can range from $1,200 to $1,500. Adding an NAT test effectively doubles the cost of screening organs.

But he says that NAT screens have actually allowed his organization to find more usable organs because they’ve ruled out the possibility of a recent infection in donors that previously might have been rejected solely on the basis of a high-risk medical history or lifestyle. “NAT has more than paid for itself with better utilization of donors, because we are getting more organs placed and being reimbursed for those services,” Mone says.

The CDC’s Kuehnert estimates the false-positive rate is around one in several thousand in top labs, though there’s been no published data addressing that question. Mone says that the lab used by his organization has not had a false positive in seven years.

Comments (3 of 3)

Or you could try using an HCV combined antigen/antibody assay, for a very similar price to the HCV antibody only assay, the same baisc turnaround, and although not quite as sensitive as NAT, certainly very close for HCV!